hurd: Implement faccessat without AT_EACCESS flag

* hurd/hurd/fd.h: Include <fcntl.h>
(__hurd_at_flags): New function.
* hurd/lookup-at.c (__file_name_lookup_at): Replace flag computation
with call to __hurd_at_flags.
* include/unistd.h (__faccessat, __faccessat_noerrno): Add declaration.
* sysdeps/mach/hurd/access.c (access_common): Move implementation to
__faccessat
(hurd_fail_seterrno, hurd_fail_noerrno): Move to sysdeps/mach/hurd/faccessat.c.
(__access_noerrno): Use __faccessat_common instead of access_common.
(__access): Likewise.
* sysdeps/mach/hurd/euidaccess.c (__euidaccess): Replace implementation
with a call to __faccessat.
* sysdeps/mach/hurd/faccessat.c (faccessat): Rename into...
(__faccessat_common): ... this. Move implementation of __access into it when
AT_FLAGS does not contain AT_EACCESS. Make it call __hurd_at_flags, add
reauthenticate_cwdir_at helper to implement AT mechanism.
(__faccessat_noerrno): New function, just calls __faccessat_common.
(__faccessat): New function, just calls __faccessat_common.
(faccessat): Define weak alias.

2 files changed, 24 insertions, 10 deletions

diff --git a/hurd/hurd/fd.h b/hurd/hurd/fd.h
index 7fd2297779..809a73f5dd 100644
--- a/hurd/hurd/fd.h
+++ b/hurd/hurd/fd.h
@@ -26,6 +26,7 @@
 #include <hurd/hurd_types.h>
 #include <hurd/port.h>
 #include <sys/socket.h>
+#include <fcntl.h>
 
 
 /* Structure representing a file descriptor.  */
@@ -254,6 +255,26 @@ extern int _hurd_select (int nfds, struct pollfd *pollfds,
 			 const struct timespec *timeout,
 			 const sigset_t *sigmask);
 
+/* Apply AT_FLAGS on FLAGS, in preparation for calling
+   __hurd_file_name_lookup.  */
+
+_HURD_FD_H_EXTERN_INLINE error_t
+__hurd_at_flags (int *at_flags, int *flags)
+{
+  if ((*at_flags & AT_SYMLINK_FOLLOW) && (*at_flags & AT_SYMLINK_NOFOLLOW))
+    return EINVAL;
+
+  *flags |= (*at_flags & AT_SYMLINK_NOFOLLOW) ? O_NOLINK : 0;
+  *at_flags &= ~AT_SYMLINK_NOFOLLOW;
+  if (*at_flags & AT_SYMLINK_FOLLOW)
+    *flags &= ~O_NOLINK;
+  *at_flags &= ~AT_SYMLINK_FOLLOW;
+  if (*at_flags != 0)
+    return EINVAL;
+
+  return 0;
+}
+
 /* Variant of file_name_lookup used in *at function implementations.
    AT_FLAGS may only contain AT_SYMLINK_FOLLOW or AT_SYMLINK_NOFOLLOW,
    which will remove and add O_NOLINK from FLAGS respectively.
diff --git a/hurd/lookup-at.c b/hurd/lookup-at.c
index abf9047e57..deddc2264c 100644
--- a/hurd/lookup-at.c
+++ b/hurd/lookup-at.c
@@ -29,16 +29,9 @@ __file_name_lookup_at (int fd, int at_flags,
   error_t err;
   file_t result;
 
-  if ((at_flags & AT_SYMLINK_FOLLOW) && (at_flags & AT_SYMLINK_NOFOLLOW))
-    return (__hurd_fail (EINVAL), MACH_PORT_NULL);
-
-  flags |= (at_flags & AT_SYMLINK_NOFOLLOW) ? O_NOLINK : 0;
-  at_flags &= ~AT_SYMLINK_NOFOLLOW;
-  if (at_flags & AT_SYMLINK_FOLLOW)
-    flags &= ~O_NOLINK;
-  at_flags &= ~AT_SYMLINK_FOLLOW;
-  if (at_flags != 0)
-    return (__hurd_fail (EINVAL), MACH_PORT_NULL);
+  err = __hurd_at_flags (&at_flags, &flags);
+  if (err)
+    return (__hurd_fail (err), MACH_PORT_NULL);
 
   if (fd == AT_FDCWD || file_name[0] == '/')
     return __file_name_lookup (file_name, flags, mode);